Hach-Lange DR 3900 User Manual - Manual (Page 105)

105
Expanded programs
5. Press Return to return to the Scan mode.
Note: The Integral is shown instead of the date on the display.
Note: For the next scan reading the setting for the Integral will be On.
Scale & Units
1. Press Options>More..>Scale & Units.
2. Highlight the required units (Abs or %T).
3. Highlight Auto or Manual scaling on the graph's y-axis.
Note: When selecting the manual scaling, the limit values y
min
and y
max
can be entered using the alphanumeric keypad. The graph is adjusted to
display only the values in the selected range. If automatic scaling is
selected, the instrument sets the limits automatically so that the total
range can be displayed.
4. Press OK.
5. Press Return to return to the Scan mode.
6.6.2 Perform a wavelength scan
After selecting all scan parameters, record a base line (initial zero
reading). If a scan parameter is changed, a new base line must
be recorded. When the baseline has been scanned, the
instrument is ready to scan one or more samples.
1. Select in the main menu the menu option Wavelength Scan.
2. Insert the zero solution cell into the cell compartment and
close the cell compartment cover.
Note: The cell compartment must be closed via the cell
compartment cover during a scan. Therefore, no scans can be
performed with 13-mm round cells.
3. Press Zero.
"Zeroing" is shown below the graph as the baseline scan
begins.
4. Insert the prepared analysis cell into the cell compartment
and close the cell compartment cover.
5. Press Read.
Under the graph, the display "Reading..." appears, and a
graph of the absorbance or transmittance values for the
scanned wavelengths is continuously displayed.